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The answer to redder plants?
- Thread starter Team Steve
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- red plants
Ah It didn't meant to turn out like that as I do have plants with red in my low light setups such as ludwigia repens but only the leaves at the top which made me have that theory. After reading your post once more I acknowledge where your coming from and I do think you are right. It can also translate to why some crypts like wendtii will stay relatively red even though they don't reach to the top of my aquarium whilst being shaded by swords in my.
Michael.
Errr..leaves turn colors in the Autumn because the Nitrogen in the Chlorophyll is reclaimed in preparation for Winter so that when spring comes, the new growth will not suffer Nitrogen shortage. It is not solely in response to cooler weather or for just for protection. The plant "knows" when Winter is coming so this is a preparation.
You will not find any direct relationship between pigment changes and pH. Plants really do not care about external pH in-and-of itself.
There are a combination of factors that affect the pigmentation changes in aquatic plants. The factors are not always the same for different species. In general, the purpose of pigments has to do with the ability to harvest the energy of various wavelengths of light or to reflect and protect the plant from excessive energy of certain wavelengths. Chlorophyl is a green pigment which uses Nitrogen in it's molecular structure. Other pigments, such as Carotene are orange/red and do not contain Nitrogen, therefore in some cases, under a Nitrogen shortage, there is a lack of Chlorophyl in relation to Carotene or other non-Nitrogen pigments which can cause the appearance of the plant to be more red since these pigments overshadow the green Chlorophyl. Thus was born the concept that a plant should be starved of Nitrogen in order to have the non-green pigments visually dominate.
While this is a plausible scenario, it is not the only one in which non-green pigments can dominate. Since the plant can respond to spectral changes, it can manufacture sufficient non-green pigments that can overshadow the green Chlorophyl. In this way it can take advantage of wavelengths of light that Chlorophyl is not optimized for.
So color changes occur under low light as well as high light for different reasons. Under low light, a pigment change may merely indicate that a re-distribution of pigment to match and take advantage of the colors being presented to the leaf. If nutrition is adequate then this enables the plant to produce the pigment in abundance.
Color changes under high light can occur in order to reflect excessive spectral energy, so that is a form of protection. Excessive energy can occur at any wavelength.
Growth rate is not necessarily relevant to pigment production and is merely coincidental. High spectral energy is correlated to high growth rates as well as to the need for protection from photoinhibition.
Cheers,
You will not find any direct relationship between pigment changes and pH. Plants really do not care about external pH in-and-of itself.
There are a combination of factors that affect the pigmentation changes in aquatic plants. The factors are not always the same for different species. In general, the purpose of pigments has to do with the ability to harvest the energy of various wavelengths of light or to reflect and protect the plant from excessive energy of certain wavelengths. Chlorophyl is a green pigment which uses Nitrogen in it's molecular structure. Other pigments, such as Carotene are orange/red and do not contain Nitrogen, therefore in some cases, under a Nitrogen shortage, there is a lack of Chlorophyl in relation to Carotene or other non-Nitrogen pigments which can cause the appearance of the plant to be more red since these pigments overshadow the green Chlorophyl. Thus was born the concept that a plant should be starved of Nitrogen in order to have the non-green pigments visually dominate.
While this is a plausible scenario, it is not the only one in which non-green pigments can dominate. Since the plant can respond to spectral changes, it can manufacture sufficient non-green pigments that can overshadow the green Chlorophyl. In this way it can take advantage of wavelengths of light that Chlorophyl is not optimized for.
So color changes occur under low light as well as high light for different reasons. Under low light, a pigment change may merely indicate that a re-distribution of pigment to match and take advantage of the colors being presented to the leaf. If nutrition is adequate then this enables the plant to produce the pigment in abundance.
Color changes under high light can occur in order to reflect excessive spectral energy, so that is a form of protection. Excessive energy can occur at any wavelength.
Growth rate is not necessarily relevant to pigment production and is merely coincidental. High spectral energy is correlated to high growth rates as well as to the need for protection from photoinhibition.
Cheers,
Team Steve
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- 34
Everyday is a school day!
But I disagree with how you say there is no direct relationship between pigment changes and pH, take blueberrys which contain the same pH sensitive anthocyanins that you would find in aquatic plants. Blueberrys being blue when more alkaline and more red when acidic. This being based on the soil the plant is planted in and in the same line the soil and water the aquatic plant is planted in.
You got a point.
hoggie
hoggie
Well, it's a real stretch comparing blueberries using soil uptake as a terrestrial plant with an aquatic plant using foliage uptake. One needs to be very careful to compare these two very different environments because they have very different mechanisms. Some processes are very similar, but there are enough disconnects between the physiology and the chemistry of soil/air and water that you need to be very careful to study each process. Secondly, you are comparing the pigment strategy and architecture of a fruit to the color pigment strategy of a leaf.
First of all, unless the tank has a very high alkalinity (KH) the pH in a CO2 injected tank is not really constant specifically because of the injection of the gas. Typically, there is as much as a 1 pH unit swing between night and day. At nigh, when pigments are not in use, the pH is higher and is as steady as it gets, but even so, the pH rises as CO2 escapes the water and steadily rises from gas on, well into the photoperiod for many folks. So you'd have to do some very careful tests, using CO2 and KH to shift the pH excursions up or down to compare.
Then, you'd have to make sure that a pigment change was repeatable and also, more importantly, you'd have to ensure that pigment changes wasn't due to some other factor, which is difficult if you don't know what all the other possible factors are. Here's what I mean by that:
Here is Blyxa japonica (on the left) at pH 6.2:
Here are cuttings from the same specimen at the same pH 6.2 some time later:
So, the CO2 and pH profile stayed as constant as one can hope to achieve with solenoid, timer and regulator during the few months between the two photos (which may also be a stretch) and yet the plant changed color. What changed most significantly from first to second photo is a light bulb change as well as an increase in the nutrient dosing.
Could those have been factors? Possibly.
Could it be other factors we hadn't even considered? Unclear.
Does it demonstrate that pH changes has no effect on color changes? No, not at all.
It only shows that pH possibly is NOT a sole factor, if at all, because the pH profile stayed the same during the color transition.
I did not check this in a low tech tank or in a liquid carbon tank where the pH is much more steady since there is no injection, or even a tank whose pH is manipulated by a pH Controller, but that might be something you should try. Even if you used a controller to keep steady pH that will occur at the cost of CO2 variation, which then could not be eliminated as a possible cause.
I would not simply draw a conclusion based on the analog of the blueberry. Certainly, in an injected tank, micromanaging pH is a bad idea anyway because of the phenomenon of Carbonic acid formation, so controlling color using pH would not always be an available option.
Cheers,
First of all, unless the tank has a very high alkalinity (KH) the pH in a CO2 injected tank is not really constant specifically because of the injection of the gas. Typically, there is as much as a 1 pH unit swing between night and day. At nigh, when pigments are not in use, the pH is higher and is as steady as it gets, but even so, the pH rises as CO2 escapes the water and steadily rises from gas on, well into the photoperiod for many folks. So you'd have to do some very careful tests, using CO2 and KH to shift the pH excursions up or down to compare.
Then, you'd have to make sure that a pigment change was repeatable and also, more importantly, you'd have to ensure that pigment changes wasn't due to some other factor, which is difficult if you don't know what all the other possible factors are. Here's what I mean by that:
Here is Blyxa japonica (on the left) at pH 6.2:
Here are cuttings from the same specimen at the same pH 6.2 some time later:
So, the CO2 and pH profile stayed as constant as one can hope to achieve with solenoid, timer and regulator during the few months between the two photos (which may also be a stretch) and yet the plant changed color. What changed most significantly from first to second photo is a light bulb change as well as an increase in the nutrient dosing.
Could those have been factors? Possibly.
Could it be other factors we hadn't even considered? Unclear.
Does it demonstrate that pH changes has no effect on color changes? No, not at all.
It only shows that pH possibly is NOT a sole factor, if at all, because the pH profile stayed the same during the color transition.
I did not check this in a low tech tank or in a liquid carbon tank where the pH is much more steady since there is no injection, or even a tank whose pH is manipulated by a pH Controller, but that might be something you should try. Even if you used a controller to keep steady pH that will occur at the cost of CO2 variation, which then could not be eliminated as a possible cause.
I would not simply draw a conclusion based on the analog of the blueberry. Certainly, in an injected tank, micromanaging pH is a bad idea anyway because of the phenomenon of Carbonic acid formation, so controlling color using pH would not always be an available option.
Cheers,
Team Steve
Member
- Joined
- 30 Jun 2013
- Messages
- 34
Really interesting read, as I know each plant is different. So each one has have a certain criteria for it to show the colors that we want to see, the only reason I ever went with my pH theory is because it was one parameter I never saw quoted and based on the original journal I was reading, the tank was receiving optimal ferts, CO2 and light.
So how I stand now is that its the bigger picture that needs to be looked at (optimum ferts, CO2, light for each individual species to hit the "sweet spot") OR at a stretch there could be certain unexplored triggers for each individual species.
So how I stand now is that its the bigger picture that needs to be looked at (optimum ferts, CO2, light for each individual species to hit the "sweet spot") OR at a stretch there could be certain unexplored triggers for each individual species.
Hi,
Yes, I agree with your assessment. I don't have much trouble getting colors in my plants, and even if the color isn't red, it's usually a very interesting color, like orange or yellow. This occurs without my trying to manipulate pH.
Some species color up on the underside of the leaf equally or more so than on the top side. Other species are completely unpredictable. In the case of Blyxa, the colors appeared when I didn't even want them to. It's such a complicated issue that it's not really worth focusing too much on any one parameter. A better path is to simply get plants that are known to be red under most conditions, such as Althernanthera or R. macandra, then just ensure good CO2/flow/nutrients. We know that high lighting will trigger pigment reallocation, so as long as you can keep up with the escalated requirement of flow/distribution and CO2/nutrition that automatically emerges when the spectral energy increases, then you can get many colors to appear.
One of the most influential factors that many ignore when comparing the specimens in their tank versus anothers is that of genetic variation. The specimens in your tank may not be as predisposed to that particular pigment development as another specimen from a different location.
Cheers,
Yes, I agree with your assessment. I don't have much trouble getting colors in my plants, and even if the color isn't red, it's usually a very interesting color, like orange or yellow. This occurs without my trying to manipulate pH.
Some species color up on the underside of the leaf equally or more so than on the top side. Other species are completely unpredictable. In the case of Blyxa, the colors appeared when I didn't even want them to. It's such a complicated issue that it's not really worth focusing too much on any one parameter. A better path is to simply get plants that are known to be red under most conditions, such as Althernanthera or R. macandra, then just ensure good CO2/flow/nutrients. We know that high lighting will trigger pigment reallocation, so as long as you can keep up with the escalated requirement of flow/distribution and CO2/nutrition that automatically emerges when the spectral energy increases, then you can get many colors to appear.
One of the most influential factors that many ignore when comparing the specimens in their tank versus anothers is that of genetic variation. The specimens in your tank may not be as predisposed to that particular pigment development as another specimen from a different location.
Cheers,
